George Adams, Jr., was English instrument maker who developed many electrical instruments and their application, particularly in medicine. He wrote many important scientific books, including famous “Essay on Electricity” (1784).
George Adams, Jr., was born in Southampton in 1750. His father, George Adams, Sr., was one of the most important English instrument makers in the second half of the eighteenth century. The senior Adams published a popular work, “Micrographia Illustrata” (1746), and introduced a number of improvements in microscope design. George Adams, Sr. also made many other scientific instruments.
After George Sr.’s death in 1773, the company he founded was managed by his sons, George Jr. and his younger brother Dudley. George Adams, Jr., was a leading maker of mathematical instruments. He was instrument-maker to George III and optician to the Prince of Wales. King George III awarded him an annual sum of money and Adams teached several others in the art of instrument making.
Succeeding his father as Instrument Maker to His Majesty King George III in 1773, George Adams, Jr. was also later designated Optician to the Prince of Wales. Many attributes of this barometer show why he was considered one of the finest instrument makers of the 18th century. The quality of the timber, mouldings, and cabinetry in general are of the finest; touches such as the geared hygrometer, brass door catch, and beautifully engraved and annotated scales are typical of his products.
Adams was the author of a large number of elementary scientific works, which according to a writer in the “British Critic,” were so planned as ‘to comprise a regular and systematic instruction in the most important branches of natural science with all its modern improvements.” He also wrote largely on the use of mathematical instruments, and his books on that subject were highly valued.
In many of his published works he combined a religious with a scientific aim, and ‘applied all his knowledge,’ says the ‘Gentleman’s Magazine,’ ‘to the best of purposes-to combat the growing errors of materialism, infidelity, and anarchy’. Adams published a wide range of works on various scientific topics, including “Essay on Electricity” (1784), “Essays on the Microscope” (1787), “Astronomical and Geographical Essays” (1789), “Essay on Vision” (1789) “Geometrical and Graphical Essays” (1791), “Lectures on Natural and Experimental Philosophy” (1794).
Demonstrations of electrical effects became more common after the invention around 1747 of the Leiden jar. The jar stored electric charge, and so allowed more impressive demonstrations. This version of an electrical machine was made by George Adams Senior around 1762. The glass cylinder is turned using the handle so that it rubs against a fabric-covered pad and causes a charge to build up. The charge can be conducted away from the brass back plate of the pad and used to make sparks.
This illustration shows a young girl being treated electrically, for pain or paralysis of the forearm. Adams’ cylinder generator is at the right, and the main terminal is in the center with a Leyden jar hanging from a metal rod terminated by a metal globe. A metal chain goes from the base of the Leyden jar to a treatment electrode touching the girl’s upper arm. The other treatment electrode is connected to a Lane discharging electrometer mounted on the main terminal near the Leyden jar.
The electrometer is an adjustable spark gap. Voltage will build up in the main terminal, and the Leyden jar, until the voltage is high enough to leap the gap. Then all the electricity will be carried down the chain to the treatment electrode. The result will be a powerful shock of electricity applied to the girl’s forearm. The size of the shock can be adjusted by the size of the gap the Lane electrometer provides. A shock like this is a powerful stimulus to nerve and muscle.
It can deaden pain, or exercise paralyzed muscles for physical therapy. We still do these things today, with more sophisticated equipment — the TENS (transcutaneous electro-neural stimulation) unit for treatment of pain, and the neuromuscular stimulator for physical therapy.
Three illustrations showing the Adams’s instruments. From George Adams, “An Essay on Electricity: Explaining the Theory and Practice of that Useful Science, and the Mode of Applying it to Medical Purposes”, 4th ed. (London, 1792).
George Adams, Jr. wrote several books related to other areas of science including: “Essays on the Microscope” and “Geometrical and Graphical Essays”.
Adams’ book “Essays on the Microscope” (1787) was a very important book of his time that made big influence on the development of microscopes.
The Cuff-type instrument is attached to the box-foot by a square pillar, which supports the body-tube, stage and the mirror. Focusing is by rackwork that moves the stage. The drawer includes accessories (objective lenses, Lieberkuhn reflector, fish plate, stage forceps, and brass slider.) The whole instrument fits into a pyramid-shaped mahogany case upon removing the body-tube. The instrument is very similar to the “Improved Double and Single Microscope,” featured in Adams’ “Essays on the Microscope” (1787). This microscope was signed: G. Adams No 60 Fleet Street London.
This unsigned, brass instrument is very similar to the “Improved Compound Microscope” shown in Adams’ “Essays on the Microscope” (1787). The folding tripod base supports the round, tapered pillar. The round limb, attached to the pillar by a compass joint, holds the platform fitted with a spring stage and the arm, supporting the body-tube. A swinging mirror slides along the square-section bar attached to the limb.
The instrument fits into a wooden case, and no accessories are present, except an ivory slider. It is possible that this is a German copy of the Adams model, as the construction of the box, lined with olive green woolen cloth and mahogany inlaids, appears different from the boxes of English instruments.
This microscope is an example of a simple dissecting microscope designed by Pieter Lyonnet, but probably built by George Adams Junior in the late 1700s. This style microscope was very popular with naturalists of the period and several different varieties were sold by many instrument makers, most notably George Adams and John Dollond. Peter Lyonnet first described an instrument (similar to the one illustrated here) for micro-dissection in the mid 1700s to members of the Dutch Society of Science.
The microscope presented here is housed on a wooden box base containing a drawer for storage of specimens and accessories. Attached to the base is a brass pillar and a planar mirror hinged on a gimbal. An oval mahogany table is positioned at the top of the pillar and contains an aperture (hole) through which the specimen is illuminated by the mirror. Offset on the table is a brass boss that secures a sequence of Musschenbroek swivel nuts that hold a brass-mounted lens.
In lucernal microscopes, the observer’s eye and the objective are conjugate with a large convex lens mounted on one end of a body tube. Light from the objective is projected from the condensing lens onto the eye or a ground glass focusing screen. In the illustration above, however, an end piece of the rectangular mahogany housing covers the focusing screen, a feature that provides protection from damage and dirt when the microscope is not in use. Also, the tripod foot that supports the brass cylindrical pillar (topped by a compass joint) may be folded flat to reduce storage space requirements.
Focus of this instrument is accomplished by turning either of the knobs that are mounted on the pillar, an action that moves the stout, horizontal brass bar supporting the microscope back and forth. A stage at the front of the horizontal bar, which is designed for holding opaque specimens, is illuminated by a bull’s-eye condenser and a concave mirror. The compound, 205-millimeter body tube of the instrument is fitted with an eyepiece composed of two biconvex lenses and a biconvex field lens. A brass-mounted projection lens that protrudes from the wooden projection box completes the device’s optical system.
Accompanying the instrument is a brass, telescoping simple microscope, featured in the lower right-hand corner of the illustration. The smaller microscope serves as an eye-locator for high-powered objectives that do not adequately illuminate the focusing screen. There is also a spring stage in the lower left-hand corner that features a condenser in a sliding tube and rectangular frame, which can be used to tie down frogs and other specimens for observation or dissection.
George Adams’ book “Geometrical and Graphical Essays”, 1791, describes many other scientific instruments of that time.
The instrument has a 7.25″ horizontal circle, a partial 7.25″ vertical circle, and a 4″ needle. The vertical circle is divided from. The telescope is 13.2″ long. The instrument is inscribed “G. Adams, London.” The upper horizontal limb under the objective end of the telescope has divisions, noted by the inscribing “Tang. to 100 of Radius.” The leveling base has a spring-opposed tangent screw, which is apparently a retrofit since there is no evidence the spring-opposed feature was used in the 18th century. The instrument is depicted on Plate 16 of George Adams’ “Geometrical and Graphical Essays”, 2nd ed., 1797.
The maker of this globe was George Adams, Jr. This globe is mounted on a four-legged wooden stand. The horizon is 6 cm. wide and made of wood. There is a brass meridian circle.
An extremely rare and important 18th-century planetarium by George Adams, Jr., Scientific Maker to His Majesty King George III. This extraordinary instrument is a functional model of the solar system as it was known in the late 18th century, with the seven known planets and their moons. An intricate system of gears allows the planets and their moons to revolve around the sun, each at their proper and varying speed, by turning its ivory handled crank.
Such a sophisticated instrument required a superior understanding not only of astronomy, but of mathematics and mechanics. George Adams, Jr., like his father, possessed just such an intellect and was widely regarded among the finest makers of the late 18th century, evidenced by his prestigious appointment by King George as Royal Scientific Maker. A similar example made for the King is now in the permanent collection of the Victoria and Albert Museum in London.
This apparatus illustrates all the mechanical powers. It consists of the balance, pulleys, levers, inclined plane, wheel and axle, screw, compound engine, compound lever, double cone, friction wheels, weights and wedge. This apparatus was made my George Adams the younger, instrument maker to the king as his father had been. Mechanical powers apparatus, 1775
Although this was possibly made by Adams to be used with his electrical machine, it is more likely to be the ‘musical bells’ listed in the items made by Adams the Younger for the Prince of Wales during the 1780s. It is typical of his style and the period. Electric chimes, last quarter 18th century
This instrument was used to measure and do calculations. Sectors were made with scales suited to different trades. Scales are based on lengths and angles, as well as logarithmic and trigonometric functions. In politics George Adams was a staunch tory, and as such was received with favour at court by George III.